Meanwhile, position rack in bottom third of oven and preheat to 400°F. Pour remaining custard into ramekins. Brush exposed bread pieces with melted butter. Sprinkle with 1 tablespoon sugar. Set ramekins in large roasting pan. Pour enough hot water into pan to come halfway up sides of ramekins. Bake puddings until set and knife inserted into custard comes out clean, about 45 minutes. Remove from pan; cool. DO AHEAD: Can be made 8 hours ahead. Cover and refrigerate.